1. Field of the Invention
This invention generally relates to wireless communications and more particularly to a modular wireless multimedia device operable to support enhanced call functions.
2. Background of the Invention
Wireless communications offer users the ability to be “wired” from almost anywhere in the world. Cellular telephones, satellite telephones, wireless local area networks, personal digital assistants (PDAs) with radio frequency (RF) interfaces, laptop computers with RF interfaces and other such devices enable these wireless communications. Such wireless communications have been extended to personal wireless networks, such as these defined by the Bluetooth specification. Not only have cellular telephones become very popular, but Wireless Local Area Networking (WLAN) devices have also proliferated. One standard for wireless networking, which has been widely accepted, is the Specification of the Bluetooth System, v. 1.0 (“Bluetooth Specification”).
The Bluetooth Specification enables the creation of small personal area networks (PAN's) where the typical operating range of a device is 100 meters or less. In a Bluetooth system, Bluetooth devices sharing a common channel sequence form a piconet. Two or more piconets co-located in the same area, with or without inter-piconet communications, is known as a scatternet.
The Bluetooth Specification supports voice communications between Bluetooth enabled devices. When a pair of Bluetooth devices supports voice communication, the voice communications must be wirelessly supported in a continuous fashion so that carried voice signals are of an acceptable quality. One popular use of personal wireless networks couples a wireless headset(s) with cellular telephone(s), personal computer(s), and laptop(s), etc. The Bluetooth Specification provides specific guidelines for providing such wireless headset functionality.
Bluetooth provides a headset profile that defines protocols and procedures for implementing a wireless headset to a device private network. Once configured, the headset functions as the device's audio input and output. As further defined by the Bluetooth Specification, the headset must be able to send AT (Attention) commands and receive resulting codes, such that the headset can initiate and terminate calls. The Bluetooth Specification also defines certain headset profile restrictions. These restrictions include an assumption that the ultimate headset is assumed to be the only use case active between the two devices. The transmission of audio is based on continuously variable slope delta (CVSD) modulation. The result is monophonic audio of a quality without perceived audio degradation. Only one audio connection at a time is supported between the headset and audio gateway. The audio gateway controls the synchronous connection orientated (SCO) link establishment and release. The headset directly connects and disconnects the internal audio stream upon SCO link establishment and release. Once the link is established, valid speech exists on the SCO link in both directions. The headset profile offers only basic inoperability such that the handling of multiple calls or enhanced call functions at the audio gateway is not supported. Another limitation relates to the manner which Bluetooth devices service only single channel audio communications. In most cases, the Bluetooth device is simply a replacement for a wired headset. Such a use of the Bluetooth device, while providing benefits in mobility of the user, provides little additional benefit over wired devices. Because other wireless solutions provide many of the benefits that current Bluetooth devices provide in servicing voice communications, the needs for the complexities of the Bluetooth Specification are questioned.
Thus, there is a need for improved operations by WLAN devices servicing audio or multimedia communications that provide additional user functionality and improved service quality.